The post office set up locations Thursday for residents of the area devastated by Hurricane Katrina (search) to pick up their first-of-the-month checks, and said it is no longer accepting magazines or bulk mail for delivery to the damaged area.

Dozens of post offices were closed and mail service was suspended in parts of Louisiana, Mississippi and Alabama. But officials said they are working to get mail to people.

"We realize how important it is to get this mail through," Deputy Postmaster General Patrick R. Donahoe (search) said in a telephone interview. Vital mail includes such things as Social Security and pension checks, paychecks, insurance forms and medicine shipped by mail.

Thousands of people have been evacuated from their homes and Donahoe urged them to contact the post office with their new address, even if it is temporary.

"Change your address, the mail will follow you," he said.

First-class mail for New Orleans (search) is currently being held in Dallas and will be forwarded from there, Donahoe said.

Meanwhile, the agency has set up temporary centers where people can pick up their Social Security (search) checks and public assistance checks.

Some banks are "coming to life" in the area, Donahoe said, "so we need to get these checks in people's hands."

"We physically can't make the deliveries because of the road situation and because a lot of our trucks were destroyed," he said.

Pickup centers have been set up in Escatawpa, Biloxi and Gulfport, Miss., and in Louisiana at Hammond, Covington, LaPlace and Des Allemands. A center is also planned for the Mobile, Ala., area.

Donahoe said that mail service in Mississippi is close to normal in Jackson and to the north, although the agency is facing a shortage of gasoline in some rural areas.

Service remains disrupted south of Jackson, particularly close to the ocean, he said.

In Louisiana, mail service is largely up and running in Shreveport, Alexandria, Baton Rouge, Lafayette and northern areas, Donahoe said.

"In New Orleans we are under water like everyone else," he said, "we are not back."

The post office will not seek to return to service in the city until local authorities declare it safe.

"We are holding mail at this point," he said, and people can receive delivery by filing a change of address with postal officials.

He said the post office is working with the Red Cross and authorities in Houston to determine who has been evacuated to the Astrodome and forward their mail to them.

The post office told advertisers and publishers to stop sending items to the devastated area to keep the system open for movement of needed First Class mail to the region, he said. In addition, he added, "We don't want people spending money for postage we can't deliver."